In the process of packaging goods in boxes made of cardboard, plastic foil, etc., the boxes are initially in the form of blanks stackable for convenient transport. The blanks must be broken open and erected prior to filling with consumer material. Because such boxes have a tendency to close again due to internal stresses, it is frequently necessary to fold or bend the boxes into a more or less flattened form along a diagonal plane different than the one along which the blanks were formed. Such counterfolding serves to relieve a box of stresses engendered during production and transport.